// type alias
let sum :(x:number ,y:number)=>number
const result11 = sum(1,2)
type PlusType = (x:number ,y:number)=>number
let sum2: PlusType
const result22 =sum2(2,3)

type StrOrNumber = string | number 
let result3: StrOrNumber = '123'
result3 = 123

const str1:'name'='name'
const number:1=1

type Directions ='Up'|'Down'|'Left'|'Right'
let toWhere: Directions = 'Up'

interface IName {
    name: string
}
type IPerson = IName & {age:number}
let person: IPerson={name:'123',age:123}